South Koreans Amy Yang and Ko Jin-young tied for the lead in the second round at the half-stage of the HSBC Women's World Championships on Friday with five-under 67 cards as overnight leader Patty Tawtnakit endured a rough day.
Yang, who was fifth after the first day at Sentosa Golf Club, made a disappointing start with a bogey on the third hole, but she responded with four birdies in the next six.
Yang added three more gains after the turn and climbed to the top of the leaderboard in 15th place despite a blip.
Top-ranked Ko took the lead in another flawless round with five birdies and would be hoping to win the title in the tournament sometimes referred to as the "head of Asia".
Ko has had a stellar season and the 26-year-old has recorded nine top-10 finishes in his last 10 starts, including five wins.
The trio of American Megan Khang, Thai Athaya Thitikul and Canadian Brooke Henderson finished third at seven-under for the tournament.
Overnight leader Patty was down in joint-21st place after a disappointing 2021 ANA Inspiration winner's run that included five bogeys.